scholarly journals Interrelations among mixing time, power number and discharge flow rate number in baffled mixing vessels.

1985 ◽  
Vol 18 (1) ◽  
pp. 47-52 ◽  
Author(s):  
YUJI SANO ◽  
HIROMOTO USUI
Keyword(s):  
Flow Rate ◽  
Mixing Time ◽  
Power Number ◽  
Discharge Flow ◽  
Discharge Flow Rate ◽  
Mixing Vessels

EXPERIMENTAL INVESTIGATION OF ENHANCEMENT IN EFFICIENCY OF CENTRIFUGAL PUMP BY REDUCTION IN CAVITATION OF PUMP

2021 ◽  
Vol 5 (10) ◽  
Author(s):  
Gaffar G. Momin
Keyword(s):  
Experimental Investigation ◽  
Centrifugal Pump ◽  
Flow Rate ◽  
Rate Control ◽  
Flowing Liquid ◽  
Discharge Flow ◽  
Pump Performance ◽  
Cavitation Phenomenon ◽  
Discharge Flow Rate ◽  
Flow Rate Control

Cavitation phenomenon is basically a process formation of bubbles of a flowing liquid in a region where the pressure of the liquid falls below its vapour pressure and it is the most challenging fluid flow abnormalities leading to detrimental effects on both the centrifugal pump discharge characteristics as well as physical characteristics. In this low pressure zones are the first victims of cavitation. Due to cavitation pitting of impeller occurs and wear of internal walls of pumps occurs due to which there is creation of vibrations and noize are there. Due to this there is bad performance of centrifugal pump is there. Firstly, description of the centrifugal pump with its various parts are described after that pump characteristics and its important parameters are presented and discussed. Passive discharge (flow rate) control methods are utilized for improvement of flow rate and mechanical and volumetric and overall efficiency of the pump. Mechanical engineers is considering an important phenomenon which is known as Cavitation due to which there is decrease in centrifugal pump performance. There is also effect on head of the pump which is getting reduced due to cavitation phenomenon. In present experimental investigation the cavitation phenomenon is studied by starting and running the pump at various discharges and cavitating conditions of the centrifugal pump. Passive discharge (flow rate) control is realized using three different impeller blade leading edge angles namely 9.5 degrees, 16.5 degrees .and 22.5 degrees for reduction in the cavitation and increase the of the centrifugal pump performance at different applications namely, domestic, industrial applications of the centrifugal pump.

Theory of Breakdown Phenomenon at Highway Bottlenecks

2000 ◽  
Vol 1710 (1) ◽  
pp. 136-144 ◽  
Author(s):  
Boris S. Kerner
Keyword(s):  
Empirical Study ◽  
Flow Rate ◽  
Discharge Flow ◽  
Traffic Pattern ◽  
Discharge Flow Rate ◽  
Breakdown Phenomenon ◽  
Freeway Bottleneck

On the basis of an empirical study of congestion occurring at a freeway bottleneck, it is shown that the congested regime can exist under a large variation of the discharge flow rate downstream of the bottleneck. This variation can be from about 1,600 to 1,700 vehicles/h to 2,600 to 2,700 vehicles/h per lane. A criticism of the application of queuing theories for the description of traffic pattern features is given. An explanation is given of the features of a congested regime on the basis of the recently discovered properties of synchronized flow as a new traffic phase.

scholarly journals Feasibility Evaluation of Micro-Hydropower System Generation for Different Types of Sewage Treatment Plants

2019 ◽  
Vol 8 (4) ◽  
pp. 6338-6341
Keyword(s):  
Water Flow ◽  
Flow Rate ◽  
Sewage Treatment ◽  
Small Scale ◽  
Small Hydropower ◽  
Discharge Flow ◽  
Sewage Treatment Plants ◽  
Discharge Flow Rate ◽  
Hydropower System ◽  
Effluent Discharge

Small scale hydropower is among the most attractive and cost-effective sustainable energy technologies available, by harnessing electricity through moving water. Naturally, moving water can be found in rivers and also man-man conduits where there is a continuous water flow. The sewage treatment facility has continuous water flow at the effluent pipe that can generate electricity by means of small-hydropower system. However, there are no sewage treatment plants (STP) in Malaysia that reclaim the energy through the usage of water turbines. This study is conducted to evaluate the feasibility of a micro-hydropower (MHP) system at the continuous flow of effluent discharge point of domestic STP that comprises of a low head with high flow fluctuations. This work comprises of evaluation of the potential power output of MHP generator which attached to different type of STP. The work starts with selection of a five STP which have maximum current population equivalent (PE) over design PE loading ratio. Next, the effluent discharge flow rate & outfall head are collected and recorded. Finally the potential output power for all selected STPs is calculated. The highest continuous effluent discharge flow rate contributing in high potential power and will be identified as the feasible STP for the MHP system installation.

scholarly journals Experimental Measurement on Pebble Flow Discharge in a Hopper Silo Based on a Drainage Method

2021 ◽  
Vol 9 ◽  
Author(s):  
Yujia Liu ◽  
Sifan Peng ◽  
Nan Gui ◽  
Xingtuan Yang ◽  
Jiyuan Tu ◽  
...  
Keyword(s):  
Experimental Method ◽  
Flow Rate ◽  
Experimental Measurement ◽  
Experimental Results ◽  
Liquid Level ◽  
Discharge Flow ◽  
Discharge Flow Rate ◽  
Level Sensor ◽  
Liquid Level Sensor ◽  
Pebble Flow

The dropping of absorption sphere from the storage vessel under accident conditions and the transportation of spent fuel elements in the reactor will both lead to the pebble flow discharging process driven by gravity in a hopper silo. Therefore, the research on the gravity-driven discharging rate of pebbles in a hopper silo has significant engineering guidance for reactor safety. In general, the idea of falling pebbles weighing to obtain the discharging rate becomes the most common experimental measurement method. However, due to the limitation of response frequency and the disturbance of pebbles falling, the resolution of experimental results is limited, and the uncertainty is introduced into the data error, which is difficult to eliminate. In this experiment, a volume measurement based on drainage method is adopted. This is a new experimental method to measure the discharge process of hopper silo. The magnetostrictive liquid level sensor is applied to measure the rise of liquid level caused by the volume of falling pebbles. Compared with the weighing method, this method has two advantages. First, the resolution of this method has a higher controllability. On the one hand, the disturbance caused by the momentum of falling pebbles will not be introduced into this method, on the other hand, the measurement accuracy is determined by the multiple controllable factors. Second, this method can obtain higher measurement frequency. the sampling frequency of liquid level sensor is 1–2 orders of magnitude higher than that of electronictong balance. Based on this new experimental method, the reliability of the method is validated by comparing the experimental results of discharge flow rate with the Beverloo’s and Nedderman’s empirical formula. Furthermore, the effect of silo outlet size on pebble discharge flow rate fluctuation have been also analyzed in this study. By use of fast Fourier transform, the fluctuation of particle discharge flow rate is separated from the discharging sampling results of liquid level sensor.

Hybrid model for discharge flow rate prediction of reciprocating multiphase pumps

2018 ◽  
Vol 124 ◽  
pp. 53-65 ◽  
Author(s):  
Hongying Deng ◽  
Yi Liu ◽  
Ping Li ◽  
Shengchang Zhang
Keyword(s):  
Hybrid Model ◽  
Flow Rate ◽  
Discharge Flow ◽  
Rate Prediction ◽  
Discharge Flow Rate

Flow Analysis on the Effect of Rotational Speed on the Characteristics of 3-Dimentional Screw Propeller of Ship

2014 ◽  
Vol 635-637 ◽  
pp. 48-51
Author(s):  
Min Young Sun ◽  
Byung Young Moon ◽  
Gee Nam Lee
Keyword(s):  
Flow Rate ◽  
Rotational Speed ◽  
Thrust Force ◽  
Flow Analysis ◽  
Maximum Pressure ◽  
Computational Domain ◽  
Discharge Flow ◽  
Discharge Flow Rate ◽  
Screw Propeller ◽  
The Given

In this study, the commercial code was used in order to derive the discharge flow rate and the thrust force in accordance with the rotational speed of the 3-dimensional blade of screw propeller. In addition, computational domain was considered in this research and it was realized by the analysis in the blades and the outlet chamber. Furthermore, a total of 2,640,222 mesh was calculated in consideration of unstructured mesh and the analysis was performed according to the total of the rotating speed (3200, 2400, 1600, 800rpm). The analysis was carried out on the pressure distribution, discharge flow rate and consequent thrust force according to the rotational speed. Especially, the analysis was realized focusing on the condition of 3200rpm. The difference between the maximum pressure and the minimum was 5.5MPa in the given condition and the discharge flow rate as to the pressure difference was the level of 1956.67 kg/s, as the thrust force of 47083.7 F(N) was obtained. In addition, it was considered that occurrence of cavitation in the given condition is closely related the decrease of durability of screw propeller in the aspects that the thrust force on driving depends on the speed.

Analysis of the Long-Term Variations in Traffic Capacity at Freeway Bottleneck

2019 ◽  
Vol 2673 (7) ◽  
pp. 390-401 ◽  
Author(s):  
Yasuhiro Shiomi ◽  
Jian Xing ◽  
Hodaka Kai ◽  
Tomoya Katayama
Keyword(s):  
Flow Rate ◽  
Traffic Volume ◽  
Discharge Flow ◽  
Traffic Capacity ◽  
Discharge Flow Rate ◽  
Yearly Average ◽  
Breakdown Probability ◽  
Freeway Bottleneck ◽  
Capacity Drop

In this paper, the long-term variation in traffic capacity at nine typical bottlenecks on intercity expressways in Japan is analyzed. The evaluation indices of traffic capacity are defined based on three factors: the ease of phase transition from free flow to congested flow is represented by the fifth-percentile traffic volume of breakdown probability; its reliability is defined by the gap between the 50th- and fifth-percentile traffic volume of breakdown probability; and the smoothness of traffic flow after the capacity drop is evaluated as the mean of the queue discharge flow rate. The findings show that: (i) the fifth-percentile traffic volume of traffic breakdown probability shows a long-term decreasing tendency, and the values in August and December are lower than the yearly average; and (ii) the gap between the 50th- and fifth -percentile traffic volume of traffic breakdown probability and discharge flow rate tend to decrease, but the trends are not significant. Finally, we suggest that the decreasing trends might be attributed to slight changes in driving skills, driving characteristics, or vehicle types.

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